Zinc ions in an oral care formulation provide users with a number of beneficial effects. For example, zinc ions are known to have antiplaque, anticalculus, and deodorant properties. However, zinc is associated with numerous negative organoleptic properties: for example, astringency and unpleasant lingering tastes. These properties restrict the use of zinc ion-providing compounds in oral care products as a practical matter for products having negative organoleptic properties are not acceptable to consumers. Furthermore, some zinc salts such as zinc oxide have low water solubility and the activity of those zinc salts in the operating environment is typically lower than other zinc forms. This is another limitation in using zinc source in an oral care product.
A dentifrice comprising aggregated zinc oxide particles and a liquid vehicle in an amount sufficient to provide the desired consistency is known in the art. However, an oral compound containing substantially non-aggregated zinc nanoparticles, which enables use of small amounts of zinc ion without influencing activity of the zinc ion under operating environment, has not been reported yet. It is desirable to provide an oral composition which contains low level of zinc ion source but has the same or better beneficial effect of zinc ion in addition to solving the taste problem.